Applicability Statement 3 (AS3 ) is a standard via a secure data transport via the File Transfer Protocol (FTP). It is described in detail in RFC 4823rd
The AS3 standard defines a structured secure data exchange for XML, Binary, Electronic Data Interchange ( EDI - ANSI X12 or UN / EDIFACT) and other business-relevant data for data exchange by means of Multipurpose Internet Mail Extensions ( MIME). Authentication can be guaranteed by the Cryptographic Message Syntax (S / MIME) standard. An acknowledgment of receipt is done by multi-part signed replies to the original message, cf. Message Disposition Notification (MDN ).
See also: AS1 and AS2.